There is an impact absorbing device that absorbs impact when a moving body such as an airplane collides with an obstacle. In the past, an impact resistant structure of an airplane disclosed, for example, in Patent Literature 1 has been disclosed as such an impact absorbing device. The impact resistant structure of an airplane includes first and second underfloor beams that are provided on the bottom of the fuselage of the airplane and extend in directions crossing each other. Further, an impact absorber, which is made of a fiber-reinforced composite material, is provided at the crossing portion between these beams, and the first and second beams are connected to each other by the impact absorber.
Furthermore, in the impact resistant structure of an airplane disclosed in Patent Literature 1, the crossing portion between the first and second underfloor beams is a portion on which a compressive load is concentrated at the time of the crash. For this reason, it is possible to ensure structural continuity at the crossing portion between the first and second underfloor beams, and to more effectively absorb the energy of a compressive load, which is generated at the time of the crash, through crushing.